Physics 111 – 101
Fall 2008
Name ________________________________A
Exam 1
1. Which one of the choices below represents the preferred practice regarding significant figures when adding the
following: 12.4 + 11 + 67.37 + 4.201?
a. 94.971
b. 94.97
c. 95.0
d. 95
e. 90
4.201 
94.971
The number 11 has no decimal digits so the result can’t include the decimal digits
Answer is D
12.4
11
67.37
2. Which one of the choices below represents the preferred practice regarding significant figures when multiplying
the following: 10.5  8.8  3.14?
a. 290
b. 290.136
c. 290.1
d. 300
e. 290.14
10.5 8.8 3.14 
290.136
The number 8.8 has two significant digits so
you can’t have more. Answer is A
3. Water flows into a swimming pool at the rate of 8.0 gal/min. The pool is 16 ft wide, 32 ft long and 8.0 ft deep.
How long does it take to fill? (1 U.S. gallon = 231 cubic in=ches)
a. 32 hours
b. 64 hours
c. 48 hours
d. 24 hours
e. 14 hours
16 32 8
= 4096 1ft = 12 inch
Needs 3.83*10 minutes to fill = 63.8 hours
volume_in_cubic_feet
3
4096*123 = 7.078*106 /231 = 3064*104 galons
4. A triangle has sides of length 7.0 cm and 25 cm. If the triangle is a right triangle, which of the following could
be the length of the third side?
a. 18 cm
b. 24 cm
c. 27 cm
d. 32 cm
e. 14 cm
2
7
2
25 
=25.9 has no good answer.
2
25
2
7 
=24
answer B
5. A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What minimum distance must a
gazelle running 80.0 km/hr be ahead of the cheetah to escape?
a. 100 m
b. 167 m
c. 70.0 m
d. 83.0 m
e. 126 m
1
Physics 111 – 101
Fall 2008
cheetah speed in m/s
The difference
Exam 1
Name ________________________________A
gazell speed in m/s
distance made by gazelle
distance made by cheetah
Answer is B
6. A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera
records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball
during this time interval?
a. 13 400 m/s2
b. 6 720 m/s2
c. 857 m/s2
d. 20 m/s2
e. 145 m/s2
velocity is a vector. If initial is
+25 so the final velocity is - 22
-22 – 25 = 47
= answer A
7. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the final
velocity after 11 s?
a. 1.8 m/s
b. 3.2 m/s
c. 5.1 m/s
d. 0.7 m/s
e. zero
answer C
8. Norma releases a bowling ball from rest; it rolls down a ramp with constant acceleration. After half a second it
has traveled 0.75 m. How far has it traveled after two seconds?
a. 1.2 m
b. 4.7 m
c. 9.0 m
d. 7.4 m
e. 12 m
Answer E
9.
Mt. Everest is more than 8 000 m high. How fast would an object be moving if it could free fall to sea level
after being released from an 8000-m elevation? (Ignore air resistance.)
a. 396 m/s
b. 120 m/s
c. 2 480 m/s
d. 1 200 m/s
e. 12 000 m/s
Answer A
2
Physics 111 – 101
Fall 2008
Exam 1
Name ________________________________A
10. Find the resultant of the following two vectors: i) 80 units due east and ii) 50 units 30 north of west.
a. 80 units 30 north of east
b. 62 units 15 north of east
c. 44 units 60 north of west
d. 62 units 54 north of west
e. 44 units 340 north of east
vector 1 = 80i
vector 2 =
= -43i + 25j
adding = 36.6i + 25j The magnitude sqrt (36.62+252) = 44 and the angle is tan-1(25/36.6) = 340 the
answer is E


11. Vector A is 3.0 units in length and points along the positive x-axis; vector B is 4.0 units in length and points


along a direction 150 from the positive x-axis. What is the magnitude of the resultant when vectors A and B
are added?
a. 7.0
b. 6.7
c. 4.7
d. 2.1
e. 1.3
A= 3i
B = -3.4i+2j
A+B = -0.46i+2j
|A+B| =
Answer D
12. A helicopter is traveling at 40 m/s at a constant altitude of 100 m over a level field. If a wheel falls off the
helicopter, with what speed will it hit the ground? (g = 9.8 m/s2 and air resistance negligible)
a. 40 m/s
b. 50 m/s
c. 60 m/s
d. 70 m/s
e. 80 m/s
in y direction
in x direction v = 40
speed =
Answer C
13. The best leaper in the animal kingdom is the puma, which can jump to a height of 4-m when leaving
the ground at an angle of 450. With what speed in SI units, must the animal leave the ground to reach that
height?
a. 70 m/s
b. 60 m/s
c. 50 m/s
d. 40 m/s
e. 12 m/s
in y direction
at the angle of 45 deg the
velocity in x direction is the same so the speed is
Answer is E
3
Physics 111 – 101
Fall 2008
Exam 1
Name ________________________________A
14. A 5-kg block is suspended by a rope from the ceiling of an elevator as the elevator accelerates
downward at 3.0m/s2. The tension force of the rope on the block is:
A. 15 N, up
B. 34 N, up
C. 34 N, down
D. 64 N, up
E. 64 N, down
direction of acceleration is + then =mg-T=ma T = 5*10-5*3 = 35 Tension is up
Answer is B
15. A 15-kg block rests on a level frictionless surface and is attached by a light string to a 5.0-kg hanging mass
where the string passes over a massless frictionless pulley. If g = 9.8 m/s2, what is the tension in the connecting
string?
a. 65 N
b. 17 N
c. 49 N
d. 26 N
e. 37 N
T – mg = 0
T = mg = 5*10 =50 Answer is C
16. A girl is using a rope to pull a box that weighs 300 N across a level surface with constant velocity. The rope
makes an angle of 30 above the horizontal, and the tension in the rope is 100 N. What is the normal force of
the floor on the box?
a. 300 N
b. 86 N
c. 50 N
d. 250 N
e. 182 N
in y direction +N -300 +100sin(300) = N – 250 = 0
(acceleration is zero)
N = 250 Answer is D
17. A car travels east at constant velocity. The net force on the car is:
a. east
b. west
c. up
d. down
e. zero
Constant velocity means that Fnet = 0 Answer is E.
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Physics 111 – 101
Fall 2008
Exam 1
Name ________________________________A
1D 2A 3B 4B 5B 6A 7C 8E 9A 10E 11D 12C 13E 14B 15E 16D 17E
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